Dry feet is the most crucial survival thing.
Even summer time. When walking on marshland, or in heavy rain, I used to put a plastic bag on each foot, over the socks.
This summer, with my new leightweight footwear, I had to do the same.
Not much risk though of getting wet footwear during winter in the temps we are talking about.
That is the reason the Felt overboots issued in Fenno Scandia are not water proof or resistant.
If they should get wet ( forgetting to shake off snow when entering a heated area) they dry very quickly.